This invention relates generally to a power transfer mechanism incorporating a planetary gear set. More particularly it relates to a compact planetary gear assembly having a minimum number of mesh points for establishing high and low-range modes.
In recent years there have been many improvements in power transfer mechanisms, including improvements relating to planetary gearing for establishing paths for the transfer of power in high and low-range modes. Some such planetary gear sets are shifted by engaging and disengaging friction elements manually, hydraulically, electrically, or by some other suitable means. Other planetary gear sets are shifted by engaging and disengaging clutches. Normally this is done by sliding sleeves into and out of dental engagement with various elements for establishing high and low-range modes. Generally, this has required considerable space and a large number of parts within the assembly. Furthermore, in these arrangements the system generally is such that the planet and ring gears are loaded when running locked up, thus causing vibration and excessive wear.
There remains a need to provide a compact planetary gear assembly which does not require excessive space when incorporated in a power transfer mechanism, which does not load the planet and ring gears when operating in the locked-up condition, and which requires a minimum number of mesh points for effective operation.